To provide a data distribution system, a data distribution method, and the like which can supply, from an outside, data to be distributed within a network in which an access from the outside is limited.

An advertisement distribution server stores advertisement draft data 102A and 102B, and an intra-organization mail server 2-j and an intra- organization web server 3-j access an advertisement distribution server 1 to obtain the advertisement draft data 102A and 102B, within an intranet 6-j in which an access from the outside is limited by a fire wall 5-j (j is a natural number). The intra-organization mail server 2-j changes an electronic mail so as to include contents indicated by the advertisement draft data 102A to be put in a mail box 204, and makes it received by using a terminal 4-j-k (k is a natural number). The intra-organization web server 3-j changes web page data 303 so as to include contents indicated by the advertisement draft data 102B to be distributed to the intra-organization terminal 4-j-k.